This invention relates to control means for the print hammers of a printer and, more particularly, to such a control means in which the print hammers are retained in a rest position by magnetic circuit means and are displaced into the print position by the stored energy of deformable elastic bodies maintained in a deformed position by each print hammer in its rest position, the release of each print hammer being effected in response to a print command signal.
Various hammer mechanism have been proposed for high speed mechanical printers used as the output section in information handling devices. Many such printers are of the "flying" type wherein the characters to be printed are carried by a drum, a belt, or a chain which is continuously rotated, printing being effected by striking a recording device, such as a paper, against the character to be printed by means of a print hammer without interrupting the rotation of the character carrier. In a high speed printer, printing speed, and thus the speed of movement of the character carriers is extremely high. This requires rapid and precise movement of the hammer in order to assure the hammer squarely striking the correct character to assure accurate and clear printing.
Prior art flying printers generally utilized the attractive forces of an electromagnet to displace the hammer. Such arrangements generally require the use of a lever to transmit the energy, resulting from the magnetic attraction of the electromagnet, to the hammer. In other words, the hammer is directly supplied with kinetic energy or printing energy through a lever due to the attractive force of the electromagnet and, in such an arrangement, as the print energy and the kinetic energy of the lever must be supplied by the electromagnet in a very short time, the efficiency of the electromagnet is low and a very large power is required. In turn, this requires a large-scale power device which also results in the generation of substantial heat.